Security devices in the form of a multilayer tape that is adhered to the seam of an enclosure, such as a DVD case or an enclosure for electronic components, have been used where the tape includes a hologram or diffraction grating. When attempts to open the enclosure occur, the structure of the tape is disrupted and the image or pattern on the tape shows evidence of the attempt.
EMI shielding devices such as EMI shielding tapes are also known. EMI shielding tapes can be used to prevent electromagnetic interference between different components of an electronic device. Increasing device frequencies create decreasing electromagnetic wavelengths that can penetrate very small cracks or openings that may exist in an enclosure surrounding the electronic components. Device failures caused by EMI are increasing as the electronic components become more sensitive. Such tapes can be applied to seams, slots or gaps on the device to reduce EMI by creating a Faraday Cage around the electric components.
Recently, magnetic disk drives for the storage of data have been significantly reduced in size and have found use in myriad devices such as cellular telephones and personal digital assistance (PDAs). In such devices, the electromagnetic interference caused by operation of the disk drive can significantly affect the performance of the device. At the same time, disk drive manufacturers also desire to inhibit users from tampering with the device and then making false warranty claims.